Feat/close book (#9453)

* initial commit

* Add Reveal in Books editor tab context option

* Select item in books viewlet automatically

* changes

* easier than i thought it'd be

* added file watcher on toc file v1

* Merge from Feat/create book

* Undo Merge from Feat/create book

* Use fsPath instead of path

* repen book on toc update

* update book in-place

* fix close book

* error handling for closeBook

* PR comments

* addressed comments

* moved the watch block to try ,watch vs watchFile

Co-authored-by: chlafreniere <hichise@gmail.com>
Co-authored-by: Chris LaFreniere <40371649+chlafreniere@users.noreply.github.com>

extensions/notebook/package.json

@@ -186,6 +186,10 @@
           "light": "resources/light/open_notebook.svg"
         }
       },
+      {
+        "command": "notebook.command.closeBook",
+        "title": "%title.closeJupyterBook%"
+      },
       {
         "command": "notebook.command.createBook",
         "title": "%title.createJupyterBook%",
@@ -288,6 +292,10 @@
           "command": "notebook.command.searchUntitledBook",
           "when": "false"
         },
+        {
+          "command": "notebook.command.closeBook",
+          "when": "false"
+        },
         {
           "command": "notebook.command.revealInBooksViewlet",
           "when": "false"
@@ -332,6 +340,10 @@
           "command": "notebook.command.saveBook",
           "when": "view == unsavedBookTreeView && viewItem == unsavedBook && unsavedBooks",
           "group": "inline"
+        },
+        {
+          "command": "notebook.command.closeBook",
+          "when": "view == bookTreeView && viewItem == savedBook"
         }
       ],
       "view/title": [